Problem: Tommy can exchange $8$ euros for $11$ dollars. At this rate, how many dollars can Tommy get with $12$ euros?
Explanation: We're trying to find the number of dollars Tommy can get with $12$ euros. $1$ $\longrightarrow$ $1\dfrac38$ ${8}$ $\longrightarrow$ ${11}$ $ \div8$ $ \div8$ ${euros}$ $\longrightarrow$ ${dollars}$ If Tommy can exchange ${8}$ euros for ${11}$ dollars, then he can exchange $1$ euro for $1\dfrac38$ dollars. ${12}$ $\longrightarrow$ ${16\dfrac12}$ $1$ $\longrightarrow$ $1\dfrac38$ $ \times 12$ $ \times 12$ ${8}$ $\longrightarrow$ ${11}$ ${euros}$ $\longrightarrow$ ${dollars}$ So, with $12}$ euros, Tommy can exchange for ${16\dfrac12}$ or ${16.50}$ dollars.